System of motor control.



N6. 865,821. PATENTED $21 1. 10 1907.. w. J. RICHARDS.

SYSTEM OF MOTOR CONTROL.

APPLwATm: FILED MAR. 1., 1-907 WALTER .l. RICHARDS, OF

NORWOOD, OHIO, ASSIGNOR TO ALLIBDHALHERS COMPANY, A

CORPORATION OF NEW JERSEY.

SYSTEM OF MOTOR CONTROL.

Application filed March 1. 1907.

To all whom it may concern:

Be it known that I, \Ynirrnn J. RICHARDS, a citizen of the United States, residing at Norwood, in the county of Hamilton and State of Ohio, have invented certain new and useiul Improvements in Systems of Motor Con trol, 01' which the iollowing is a lull, clear, and exact specification.

My invention relates to motor control systems.

It has been lound'that one of the most eificient methods of controlling the speed 01' an electric motor is by varying the clectromotive iorce ot' the generator supplying its armature. Various systems have been devised in which this might be done.

My invention is an improvement on such systems and its object is to provide a system in which all the advantages or" said prior systems are retained while in addition there are certain other advantages, such as variation in the field strength of the motor to be controlled, and a greater simplicity in arrangement and operation.

With these objects in view, my invention comprises the combination in a motor control system, of a main motor to l)\" controlled, a gencr tor supplying the armature of said motor, a plurality of sources of current supply arranged to supply the field magnet of the generator lit't'erentially and the field winding of the motor cumulatively, and means for varying the electromotive forces of said sources.

My invention further comprises the method oi controlling an electric motor which consists in supplying its armature from a dynan\o-electric source, exciting its field by the cunnilativ action of two sources of current supply, exciting the field ot' the dynantmelectric source by the differential action of the same two sources of cur rent and varying the relation of the electromotive forces of said two sources More specifically my invention comprises the combination of a motor, a generator supplying the armature of said motor. two auxiliary generators connected in opposition through a field winding of the generator, two to assisting ficld windings for the motor each supplied by one of said two auxiliary generators, and means for varying the field strengths of said auxiliary generators in verscly.

Other features of my invention will appear from the 4 description and drawings and will be particularly pointed out in the claims The single figure oi the drawing shows diagrammatically one embodiment of my invention.

The armature A of the main motor is supplied (ii 0 rcctly by the armature ll of the generator, driven in any desired manner. The field winding 10 ot the generator is supplied by the armatures t and D oi two auxiliary genera-tors or exciters, connected in opposition and preferably driven together. The two ass t Specification of Letters Patent.

Patented Sept. 10, 1907.

sum in. 359.973.

ing field windings l1 and 12 of the motor are supplied independently by the exciters C and D respectively. The exciter field windings 13 and 14 are supplied from any suitable source of current through a switch 15. A rheostat arm 16 is movable to vary inversely the amount of the resistances 17 and 18in circuit with these two field windings respectively.

The operation or the system is as fOllOWSZ ThB gen erators B, O and D are started with the switch 15 closed, and the arm 16 preferably in its vertical or neutral position to keep the field strengths of the two exciters substantially equal. As these generators come to speed the clectroniotive forces of the exciters O and I) remain practically equal, and as these two electromotive forces are opposed throughthe winding 10 ot the main generator O, said latter generator genera-ties substantially no electromotive force. The field windings ll and 12 of the motor A however, being individually excited by the two generators" O and D respectively, are effective, so that when the generator C and D reach full speed, the field oi the motor A i at its strongest. So far, however, the motor armature A has remained at a standstill.

By moving the arm 16 to either side of the vertical,

say to thedeit as shown, the'resistance 17 is cut out of oircuit and the resistance 18 cut into circuit with the field windings 13 and 14 respectively, thereby'increasing the hold strength and consequently the electromotive force or the generator C while decreasing the field strength and consequently the elcctromotive iorce of D. The difference between these two electromotive iorccs being impressed on the field winding l0, the electromotive torce ot the armature B is gradually increased from zero to the maximum as the arm 16 moves from its vertical to its extreme left position. When this latter position is reached the circuit of the field winding M is broken and the maximum electromotive force of the generator t) is impressed on the field winding 10. As the arm 16 is moved from the vertical to the left the effect oi the motor field winding 12 is decreased while that oi the motor field winding 11 is increased. However, on account of the knees in the saturation curves oi the field magnets of the exciters O and D, the field winding 12 decreases in strength faster than the field winding 11 increases so that their combined effect is decreased. Both be cause oi the incr ase in the eleetromotive force impressed on its armature and the decrease in its'field strength the speed of the motor A is increased as the arm to is moved away from the vertical. As the arm 16' is moved back toward the vertical the reverse of the operations described above takes place and the motor A gradually decreases in speed. When the arm is moved on the right, of the vertical a cycle of operations similar to that when it is moved on the left of the vertical takes place, save that the direction of current in the field winding 10 and therefore in the armatures B and A is reversed and the motor A rotates 5 in the other direction. I

Many modifications in the precise arrangements here shown and described may be made without departing from the spirit and scope of myinvention, and in the following claims I aim to'cover all such modifications.

What I claim as new is: 5 I

1. The method of operating an electric motor, which consists in supplying its armature from a dynamo-electric source, exciting its field by the cumulative action of two sources of current supply, and exciting the field of the dynamo-electric source by-the differential action of the same two sources of current supply.

2. The method of controlling an electric motor, which consists in supplying. its armature from a dynamo-electric source, exciting its field by the cumulative action of two additional sources of current supply, exciting the field of said dynamo-electric source by the differential action of the same two sources of current supply, and varying the relation between theelectromotive forces of said two additional sources of current supply. .3. The-method of controlling an electric motor, which consists in supplying itsarmature from a dynamo-electric source, exciting its field by the cumulative action of two sources of current supply, exciting the field of the dynamoelectric source by the differential action of the same two sources 0t current supply, and varying the electromotive force of one of said sources of current supply.

4. The method of controlling an electric motor, which consists in supplying its armature from a dynamo-electric source, exciting its field by the' cumulative action of two sources of current supply, exciting the field of the dynamo electric source by the differential action of the same two sources of current supply, and varying thelectromotive forces of said two sources of current supply inversely.

The method of controlling an electric motor, which 40 consists in supplying" its armature from a dynamo-electric source, exciting its field by the cumulative action of two additional sources of current supply, exciting the field of said dynamo-electric source by the differential action of the same two sources ofcurrent supply, and varying the electromotive forces of said two additional sources of current supply.

G. A system of electrical distribution, comprising a motor, a generator supplying the armature of said motor, and two sources of current supply arranged to excite the field of the motor by their Qumulative action and the field of the generator by their diiferential action.

' 7. A system of.motor control, comprising a motor,-a plurality of sources of electromotive force, one of which is a dynamo and supplies the armature of said motor, the field of said motor being excited by the cumulative action of two of said sources, and the field of said dynamoby the differential action of the same two Sources, and means for varying the relation between the electromotive forces of said two sources. I

8. A system of motorcontroi, comprising a motor, a generator supplying the armature of said motor, two sourcesof current supply arranged to excite the field of the motor by their cumulative action and the field oi the generator by their differential action. and means for varying the electromotive force of one of said sources of current supply. A system of motor control, comprising a motor, a plurality of sources of elcctromotive force, one of which is a dynamo and supplies the armature of said motor, the held of said motor being excited by the cumulative action of two oi? said sources and the'fi eld of said dynamo by the diit'ercniial action of the same two sources, and means for simultaneously varying the ciectromotivc forces of said two sources. v 10. A system of motor control, comprising a motor, a generator supplying the armature oi said motor, two sources of current; supply arranged to excite the ilcld of the motor by their cumulative action and the iieid of the generator by their differential action, and means for simul taneously varying the electromotive forces of said two sources of current supply inversely.

11. A system of electrical distribution, comprising a motor, a generator supplying the armature of said motor, a field winding for the generator supplied by the diilercir tial action of two sources of current supply, and two iicld windings for the motor independently supplied by said two sources of current supply respectively.

12. A system of motor control, comp 'ug a motor, a generator supplying the armature of said motor, two sources of current supply, a field winding for thegenerator supplied. by said two sources of current supply in opposing series. two iield windings for the motor supplied independently by said two'sources of current supply: re spcctively, and means for varying the relation between the electromotive forces of said two sources oi current supply.

13. A system of motor control, comprising a motor, a generator supplying the 'arnmture of said motor, a field winding for the generator supplied by the differentialaction of two sources of current supply, two field windings for the motor independently supplied by said two sources of current supply respectively, and means-for varyim, the electromotive ilorce of ohefof said sources of current supply. .5 v

14. A system of motor control, comprising-n motor, a generator supplying the armature of said v motor.,.a fi eld" winding for the generator supplied hy the dili'erentiai action of two sources of current supply, two field windings fer the motorindependentlysupplied by said two sources of current supply respectively, and meanswfor simultaneously varying the electromotive:forccs. oi said two sources of current supply inversely. 1 H Y 15. A system of motor control, compri 'ng a motor generator supplying the armature of said 'motor,' two sources of current'supply, a'ficld winding for the generaior supplied by said two sources of current supplyin opposing series, two field windings for the motor supplied independently by said two sources of current supply my spectively, and means for simultaneously 'urying ihc elcctromctive forces of said two sources of current. supply.

16. A system of electrical distribution, comprising a motor, and a generator supplying the armature of said motor, the field of said generator being supplied by the ditfercntial action ottwodynamo-electric generators and the field of the motor by thecumulatlve action off-the same two generators.. n I

17. In a system of motor control, a motoigu maingcnerator supplying the armature of said motor, two add tionul dynamo electric generators, the hold of said main generator being excited bythe differential actioiuot" said I" two additional generators and the field oi' ihc motor bythe cumulative action of said two additional ccncra tors,, v and means for varying therelative iield strengihs if said two additional dynamo-electric generators.

.18. A system of motor-control, comprisinga motor; a i plurality of dynamo-electric generators. one oi? which sup.- plies the armature oi said motor, the held of said armaturesupplying-generator being. supplied by the (llll'el'cniinl action of two of said generators and the iield of the motor by the cumulative action oi two=of suid generators, and means for varying the field strength of onp of. said generators.

ll). A system ,oflmotor control, comprisinga-motor, a, pluralityof dynamo-clot 'icgencrators, oneof whichs p' M plies the armature of and motor, the fi eldfof saidarmaturesupplying generator being supplled"by thc'difiei'ential action of two of said generators and-Stile iield'of-thomotor by the cumulative action of.t h e, s ame twogcuerators, andp means for varying the field st'u gths of said two gen-f craters invcrsely. I

20. In a system of motor control, n motor, a main geu erator supplying the armature oi? said motor, twondditional dynamo-electric gencraters, v the field of said main generator being excited by the differential action of said two additional generators and the ileld oi the motor by the cumulative action of said ,two additional generators, and means for varying the field strengths of said additional dynamo-electric generators.

'11. A system oi electrical distribution, comprising a male g aerator supplyingthe armature of said generators in opposing series, and ndings for the motor supplied indessid two additional dynamo-electric genactively. A s, .tem of motor control, coinprislnga motor, a of dynamo-electric generator-sent of which sup- "notnrc of said motor, a field winding for said two a pendentlg: e1 or-.1 l

nl "operators, two as. sting field windnotor supplied independently oy the same respective and means for varying the engths of said two generators. stern of motor control. comprising: a motor, a

main go supplying the armature of said motor, two additions, lC generators. a field winding for th aim supplied by said two additional "monitors in opposing Sci .s, two assistifor iuc motor supplied independently additional vuamo-eloctric generators respecnnd 194.1. inc the field strength of one of ona dyi .moclcciric ,ecncraiors motor control, comp ncrators. one oi which sup; motor. a field winding for said upplied lw the diiferential Ling field wind- Si iplied independently by the same ..veiy, and means for varying the two gene-caters. cm 01" motor COIiIlOl, comprising a motor, a sin )l ing: thcarmaiurc oi rid motor, two field winding for two additional 'stpplicd independently namo-clcciric generators respecsupplitl uy .i'ors in op;

.ino-clcctrlc machine which are indcpcnd chines wnicu is supplied hy said two additional sources of current supply i series, two iield windings for the other dynamo-cl z'ic m chine which are independently supplied it urccs of current supply rcspcc- .vciy, and ill yinp; the clcctromotive forces of d two additional sources of current supply.

'ical distribution, comprising,- two ic m chines, two auxiliai'y sources of current, winding for one oi said dynamo-electric machines is supplied by said two additional sources of curin .erics, two field windings for the other s ppi dng generator supplied by the differential ing a motor. a-

dynamo-electric machine which are independently supplied by said two additional sources of current supply rcspec tlvely, and means for varying the electromotive forces of said two additional sources of current supply inversely.

29. In a system of electrical distribution, two main dynamo-electric machines, two auxiliary dynamo-electric generators, a field winding for one of said main dynamoelectric-machincs which is supplied by said two auxiliary generators in series, and two field windings tor the other main dynamo-electric machine which are independently supplied by said'two auxiliary generators r pectlvely.

80. In a system of electrical distribution, two main dynamo-electric machines, two auxiliary dynamoclectric generators, a field winding for one of said main dynamoelectric machines which is supplied by said two auxiliary generators in series, two field windings for the other main dynamo-electric machine which are independently supplied by said two auxiliary generators respectively, and means for varying the craters. p 4

31. In a system of electrical distribution, two min dynamo-electric mnchinesmtwo auxiliary dynam lcctiic generators, a field winding; for one or said main dynci electric machines which is supp ied by said two auxiliary generators in series, two field windings for the other main dyuanio-electrlc machine which are independently supplied by said two auxiliary generators respe tively, and means for varying the licld streng-v is or said two an iary generators inversely.

32. In a system of electrical distribution, two dynamo electric machines, two exciters, a field winding; for one of said dynamo-electric machines supplied by said excitnrs in series, two field windings for other dynamlrelectric machine supplied independent said two excitcrs resopctively, resistances in the f circuits, of the excitors. and means i'oizvarying s. i st .nces.

33. in a s stem of ch; tr al distribution, two dynamo electric machines, two e." itc a iicld windingfor one of field strengths of said two auuiliai; gensaid dynamoclectric machines supplied by said excitcrs in series, two field windin' for the other dynamorlcctric machine supplied independently by said two exciters rcspectivcly, resistances in the iield circuits of the 0X rs, and means for varying said resistances inversely.

Iii. In a system of electrical distribution. two dynamoclcctric machines. two cxcltcrs. a field winding for one of said dynamo clcctric machines which is supplied by said two excitcrs in series, two field windings for the other dynamoelcctric machine which are supplied independently lay said two exciicrs respectively. and a unitary means for varying the resistance or the c. liIGl' field circuits.

35. In a system of elecirical distribution, two dynamoelectric machines, two cxciters, a field winding for one oi. said dynamo-electric machines which is supplied by said twoexcitcrs in series, two field windings for the other dynamo-electric machine which are supplied independently by said two cxcitcrs respectively, and a unitary means for varying inversely the resistance 01' the cxcitcr field circuits.

' In testimony whereof I ailix my signature, in the presence of two witnesses. 

